It is believed that a fuel cell includes two electrodes sandwiched around an electrolyte. It is believed that oxygen, e.g., from air, passes over one electrode and hydrogen, e.g., from a hydrogen source, passes over the other electrode, and in a chemical reaction, generates electricity.
It is also believed that the hydrogen source can be a reformer that produces hydrogen gas as one product of another chemical reaction. It is believed that one type of reformer uses steam, oxygen, and gasoline to produce hydrogen, carbon dioxide, and carbon monoxide. Thus, it is believed that there is a need to regulate the steam pressure supplied to a reformer in a fuel cell system.